A bone grease processing station at the Mitchell Prehistoric Indian Village: Archaeological evidence for the exploitation of bone fats

Recent excavations at the Mitchell Prehistoric Indian Village, an Initial Middle Missouri site in Mitchell, South Dakota have revealed a large, clay-lined feature filled with fractured and fragmented bison bones. Fracture and fragmentation analysis, along with taphonomic evidence, suggests that the bones preserved within the feature represent evidence of prehistoric bone marrow and bone grease exploitation. Further, the character of the feature suggests that it served as a bone grease processing station. Bone fat exploitation is an activity that is frequently cited as a causal explanation for the nature of many fractured and fragmented bone assemblages in prehistory, and zooarchaeological assemblages have frequently been studied as evidence of bone fat exploitation. The Mitchell example provides some of the first direct, in-situ archaeological evidence of a bone grease processing feature, and this interpretation is sustained by substantial analytical evidence suggesting bone fat exploitation. This new evidence provides a clearer concept of the nature of bone fat exploitation in prehistory as well as an indication of the scale and degree to which bone grease exploitation occurred at the Mitchell site. Finally, this research demonstrates the importance of careful zooarchaeological and taphonomic analysis for the interpretation of both artifactual remains as well as archaeological features.     

Carnivore competition, bone destruction, and bone density

In carnivore-modified archaeofaunal assemblages it is important to evaluate the degree to which carnivores have overprinted hominin behavioral signals. To examine the signals of increased competition for discarded bone, we present controlled experimental data on 33 simulated archaeological sites subjected to secondary consumption by spotted hyenas. We examine the relationship between competition, as measured by controlled numbers of hyenas and limb bones, and resultant levels of destruction and correlations between long-bone portion survivorship and bone density. Our results indicate that levels of destruction are equivalent regardless of the numbers of hyenas or long-bones included in the experimental assemblages. Correlations between long-bone epiphyseal and near-epiphyseal portions and bone density, however, do provide an indication of the level of competition. Results from the experimental study are used to highlight divergent levels of carnivore competition for hominin-discarded bone at the Plio-Pleistocene localities FLKN-Zinjanthropus and FLKN levels 1–2 from Olduvai Gorge, Tanzania.     

Intrataxonomic variability in metapodial and femur bone density related to age in guanaco (Lama guanicoe). Zooarchaeological and taphonomical implications

The aim of this paper is to present new information about bone mineral density (BMD) variability in guanaco (Lama guanicoe), a South American wild camelid; while taking into account its ontogenic development. The importance of considering intrataxonomic variability in bone density related to age for constructing zooarchaeological indices and applying them to archaeological assemblages is also discussed. The results presented here were developed from a large sample of 46 metacarpals and 45 femurs of modern guanacos, ranging in age from ca. 6 months of gestation to 12 years. Bone structural densities were measured using a biphotonic X-ray densitometer, DEXA method, Norland EXCELL and the bone mineral content (BMC) of each scanned portion or complete element was divided by its volume, which was obtained independently by water displacement. Our results indicate that the bone density of each anatomical unit is highly variable, even among individuals of the same species. According to metacarpals data, age is an important factor affecting BMD. Moreover, our study shows that the density ranges of different skeletal elements can overlap, suggesting that it is not possible to predict that a certain element is always denser than another one. Finally, we present new evidence about the potential age-related taphonomic bias in faunal assemblages, indicating that meanwhile some skeletal elements show clear differences in their density between their fused and unfused state (metacarpal) other do not (femur).     

Food for thought: using game cameras to better understand the movement of bones by scavenging in archaeological faunal assemblages

This paper questions our understanding of the movement of bones by animal scavengers in the archaeological record. Since assumptions regarding the effects of animal scavenging shape final interpretations of skeletal element frequencies in archaeological faunal assemblages, they are important for our understanding and reconstruction of ancient human behaviour. The results of a 4-year actualistic kangaroo scavenging study from Australia are used to question our understanding of the movement of the bone by contrasting visual data captured by motion-activated digital game cameras with traditional taphonomic studies using skeletal element frequencies. Game cameras are commonly used by ecologists to capture the behaviour of living species but have not yet been used in experimental archaeology where visually documenting animal scavenging behaviour can be used to understand the movement of carcasses and individual bones. Results suggest that traditional zooarchaeological analyses may not be accurate indicators of hunted versus scavenged prey in archaeological faunal assemblages. Moreover, they most certainly fail to document the entire suite of animals scavenging a carcass. These implications are discussed with particular reference to the ability to definitively ascertain the role of humans in the megafaunal extinction debate in Australia.     

The Use of Multiple Correspondence Analysis (MCA) in Taphonomy: The Case of Middle Helladic Asine,Greece

The goal of this paper is to investigate whether multiple correspondence analysis (MCA), a multivariate statistical technique, is a useful dimensionality‐reduction tool in zooarchaeological and taphonomic studies. For this purpose, the focus is to detect and discuss traces of waste management. Animal bones from waste‐related contexts at the Bronze Age site Asine, Greece, are investigated. The data consist of bone fragments dating to the Middle Helladic from this site. Unidentified fragments were categorised in size classes, where possible. Information on taxa, skeletal parts and the presence or absence of several taphonomic markers is included in the data set. The MCA reveals several correlations of zooarchaeological interest. For example, the association between indeterminate fragments and calcined bone points to issues concerning identification and preservation. Floors are characterised by weathered long‐bone fragments from medium‐sized mammals. Additionally, the results of MCA indicate that the material might have suffered from density‐mediated attrition, based on the abundance of axial fragments, which did not differ between different contexts and taxa. The results show that MCA can be used to detect zooarchaeological and taphonomic patterns. This multivariate technique is useful when investigating large data sets, as is often the case with large zooarchaeological assemblages. Copyright © 2016 John Wiley & Sons, Ltd.     

A taphonomic study of the African wild dog (Lycaon pictus)

Carnivore taphonomy has been traditionally used for the interpretation of archaeological sites in order to discriminate human-generated or modified from non-anthropic bone assemblages. In most of this actualistic research, the focus has mainly been placed on hyenas and felids, neglecting other carnivores. This paper analyzes the taphonomic impact of the African wild dog (Lycaon pictus) on equid bones and compares it with the bone modification patterns produced by other canids, such as wolves (Canis lupus) in order to compare medium-/large-sized canid variability on bone modification patterns and elaborate a referential framework which could be feasibly applied to the zooarchaeological record to detect canid intervention on archaeological assemblages in the past.     

New density data for unfused and fused sheep bones,and a preliminary discussion on the modelling of taphonomic bias in archaeofaunal age profiles

The analysis of mortality profiles forms an important part of zooarchaeological analysis. It has long been assumed that the bones of immature animals are more prone to taphonomic destruction than those of mature animals, potentially distorting mortality profiles. This study measures the DPD (a proxy for taphonomic strength) of the postcranial skeletons of 91 modern sheep of known age. The data produced are used to demonstrate that the DPD of unfused bones is indeed generally lower than that of their fused equivalents, although considerable inter-individual variation exists. It is further suggested that bone density increases throughout the life of an animal and occurs independently of the fusion of its bones. Consequently, taphonomic bias is partly dependant on the age structure and not the fusion status of the deposited assemblage. Relative levels of bias can only be assessed if this age structure is constant for all elements being considered (e.g. if the material were deposited as entire carcasses). Finally, because potential age-related bias is not equal for all elements, the degree of bias associated with a particular fusion group may partly depend on the numbers of certain elements within that group.     

Túnel: A Case Study of Avian Zooarchaeology and Taphonomy

Although not often considered, there are many osteological characters unique to the avian skeleton that influence the taphonomy of bird bones. These characters are reviewed and their archaeological significance discussed herein. The presence of marrow in many avian long bones is important to interpretation of avian remains from archaeological sites because the presence of marrow affects bone density and, in turn, preservation. Other structural properties that affect avian bone preservation include cortical wall thickness, length and pneumatic state. Based on an analysis of approximately 10,000 bird bones from the archaeological site of Túnel, Tierra del Fuego, Argentina, I found that specific breakage patterns resulted from natural taphonomic processes acting as a result of the unique avian bone characteristics. This information may allow researchers to distinguish breakage patterns in avian bones resulting from natural taphonomic processes from breakage patterns that are culturally induced.     

Bone Mineral Density of Wild Turkey (Meleagris gallopavo) Skeletal Elements and its Effect on Differential Survivorship

Zooarchaeologists recognize that density-mediated attrition is a bias that demands consideration in the analysis of archaeofaunal samples. This paper presents bone mineral density values (aereal and volumetric) for the wild turkey (Meleagris gallopavo) and represents the first application of Dual-energy X-ray Absorptiometry (DEXA) to birds. The relationship between density and the survivorship of avian skeletal elements and portions is demonstrated by examining 20 assemblages from the archaeological record of the northeastern United States. The results suggest that density may account for the differential survivorship of least 35% of the samples tested. Further analysis of a single site demonstrates the importance of examining bone mineral density when interpreting past bird hunting and use.     

FOCUS: on the use of the petrous bone for estimating cranial abundance in fossil assemblages

Low representation of braincase bones in zooarchaeological assemblages suggests that skulls have been intensively processed by Levantine Epipalaeolithic foragers; most cranial elements are often unidentifiable and are considered poor candidates for quantifying crania. In contrast, the petrous bone is usually found complete, and was found to be easily identifiable to body size category. Use of the petrous bone in fossil assemblages analyses leads to better estimation of the occurrence of cranial elements, and thus of skeletal part representation. We therefore suggest use of the petrous bone for detecting bone destruction and selective transport in faunal assemblages.     

FOCUS: The Scapula Representation could be the Key: A Further Contribution to the ‘Klasies Pattern’ Debate

Past discussion on the unusual skeletal part representations at Klasies River Mouth is briefly summarized. Recent discussion in this journal, regarding the “Klasies Pattern”, has focused upon the differential destruction of small and large bovid bone epiphyses by carnivore ravaging and density-mediated attrition. Bartram & Marean (1999) argue, from ethnoarchaeological study and consideration of other archaeological sites, that, unless shaft fragments are painstakingly identified, the upper limb bone epiphyses of large bovids will be seriously under-represented. They therefore suggest that the “Klasies Pattern” is likely to be artefact of taphonomic and analytical processes. Klein, Cruz-Uribe & Milo (1999) replied with a defence of the analytical procedures employed during the original Klasies River Mouth analysis. They also state that there was very little evidence of carnivore ravaging at Klasies River Mouth. In this paper, it is pointed out that Bartram & Marean's (1999) study only considered the humerus, radius, femur, tibia and metapodia. However, in the “Klasies Pattern” it is the scapula that is most notably abundant in the small bovid classes and most notably scarce in the large bovid classes. It is argued that, from the study of bone mineral densities and Brain's (1981) carnivore ravaging experiment, there is no reason to expect a differentially greater taphonomic destruction of large bovid scapulae. In fact, exactly the reverse may be true. It is therefore argued that at least this aspect of the “Klasies Pattern” must be considered to represent human differential bone transport, rather than an artefact of taphonomic processes.     

Bone density studies in zooarchaeology

Accurate bone density data are essential for assessing the influence of destructive processes in archaeological faunal assemblages. Unfortunately, the diversity of methods employed by different researchers to derive density values has resulted in recent confusion. Two recent publications in this journal [J Archaeol Sci 29 (2002) 883; J Archaeol Sci 29 (2002) 979] exemplify this state of misunderstanding. Both studies argued that the role of bone density in shaping archaeological faunal assemblages has been largely overrated, but both based their conclusions on density values that were inaccurately derived. The former employed a method of calculating bone density that has been largely discredited over the past decade [J Archaeol Sci 29 (2002) 883]. Within a larger discussion of zooarchaeological methodology, the latter provided an assessment of the current state of bone density research that inappropriately characterized the discrepancies between available sets of density data as a reflection of the differences between two technologies—photon densitometry and computed tomography [J Archaeol Sci 29 (2002) 979]. The actual dichotomy exists—irrespective of the technology employed—between studies that account for variation in the shape of bone cross-sections and those that do not. The different sets of density data currently available to zooarchaeologists vary tremendously in their accuracy. We review and evaluate the different techniques employed in the research of bone density patterns of mammalian fauna. Computed tomography produces the most accurate density data. For elements without medullary cavities, photon densitometry may provide density values of similar accuracy but only if a method of cross-sectional shape-adjustment is applied.     

Gazelle bone fat processing in the Levantine Epipalaeolithic

We investigate mountain gazelle (Gazella gazella) carcass processing to reconstruct resource intensification strategies during the Epipalaeolithic period of northern Israel. We adopt a multivariate taphonomic approach to identify the processes that most influenced bone survivorship in five gazelle assemblages. All of the assemblages are characterized by significant density-mediated biases, yet in situ attrition played a minimal role in assemblage formation. In contrast, the survivorship of hare (Lepus capensis) skeletons is not mediated by bone density indicating that different prey taxa experienced independent taphonomic histories. Both gazelle cortical and cancellous bone is highly fragmented and the degree of fragmentation and survivorship are strongly correlated with fat yields. Results of multiple tests point to intensive marrow and grease extraction as the primary determinant of gazelle bone survivorship. Although gazelle carcasses were intensively utilized throughout the Epipalaeolithic, the intensity of use is stable across the duration of the period.     

The recovery and interpretation of microvertebrate bone assemblages from archaeological contexts

The analysis of microvertebrate remains recovered from buried contexts is frequently problematic for archaeologists. Diminutive size is a major obstacle to recovering, identifying, and interpreting microfaunal bone materials successfully. Their taphonomic history is often obscure, thus the significance of microvertebrate accumulations for settlement, subsistence, and ecological interpretation is difficult to evaluate. Recognizable and reliable archaeological signatures are sought for assessing the effect of taphonomic history on microvertebrate assemblages. Relevant signatures of bone damage, skeletal survivorship, taxonomic composition, and context are examined in assemblages produced and modified through accidental non-predator-related death, predator accumulation, and postmortem alteration.     

The long–term survival of bone: the role of bioerosion

Fossil bones (N = 350) spanning more than 350 million years, and covering a wide range of depositional environments, were studied to compare the distribution of microbial destruction features in fossil bones with previously published data sets of bones of archaeological age. The distribution of bioerosion in fossil bones is very different from that found in bone from archaeological sites. Fossil bones typically show little or no bioerosion. Under normal conditions, if a bone is to survive into the fossil record, then rapid bioerosion must be prevented (or halted). This conclusion suggests that early post mortem processes,such as the mode of death, influence the potential of any bone to survive into deep time.     

Bison Bone Fragmentation and Survivorship: a Comparative Method

Zooarchaeologists usually describe a bone fragment as a particular portion or segment using terminology based on skeletal orientation (e.g. proximal, anterior, lateral). A more precise understanding of bone fragmentation can be achieved by naming portions for discrete anatomical features and defined zones. Since the anatomical features are the diagnostic criteria for identifying and orienting bones, each specimen normally has at least one such portion, and a complete element contains all of them. This recording method facilitates study of the relationship between survivorship and volume density, and it enhances inter-site comparisons. The method employs the minimum number of elements (MNE) and minimum animal units (MAU) across a site-wide aggregate. Although illustrated here with an analysis of bison bones, the method can be adapted for the study of other taxa as well as for inter-species comparisons.     

Sources of variation in carnivore tooth-mark frequencies in a modern spotted hyena (Crocuta crocuta) den assemblage,Amboseli Park,Kenya

Distributions and frequencies of carnivore tooth-marks on large mammal long-bone fragments are commonly used to infer the timing of hominin and carnivore access to prey resources in archaeofaunal assemblages. The strength of these inferences, however, is limited by a broad and currently inexplicable range of tooth-mark frequencies across experimental and archaeological assemblages. Controlling for this variation first requires that the sources be identified. Several sources of variation are examined here in an analysis of tooth-marked bone recovered from a modern spotted hyena (Crocuta crocuta) den assemblage in Amboseli Park, Kenya. Results indicate that tooth-mark frequencies: (1) depend on fragment size, (2) vary across mammals of different size classes, (3) are highly variable across equivalent portions of different long-bone elements, and (4) on certain long-bone portions are correlated with bone density and can be depressed in archaeological assemblages subjected to density-mediated attrition. Stronger inferences based on tooth-mark frequencies will require that such variation be taken into consideration, and methods for doing so are suggested.     

South American camelid bone structural density: what are we measuring? Comments on data sets,values, their interpretation and application

Bone mineral data are used in archaeology to evaluate density mediated attrition or differential preservation of archaeofaunas. For South American camelids, there are different data sets of bone mineral content. To evaluate their utility, these data sets were applied to the analysis of density mediated destruction of five archaeofaunal assemblages from Formative Period archaeological sites in the southern Calchaquíes valleys (Catamarca, Argentina) in order to evaluate interpretations achieved as an ‘end user’. Both inter- and intra-bone element density related survivorship analyses are made, concluding that for fine grain studies more complete data sets and specific analysis are required.     

A conceptual model for freshwater mussel (family: Unionidae) remain preservation in zooarchaeological assemblages

Expectations for survival of vertebrate remains have been well developed and intensely studied in the zooarchaeological taphonomic literature. Taphonomic studies of shellfish remains focus on marine species and on variables relevant to remains from paleontological contexts (e.g., fossil marine beds). In this paper we develop a conceptual framework from which to derive expectations concerning the preservation of freshwater mussel remains focusing on two parameters, shell microstructure and shell shape. Shell size does not influence survivorship. Our model is validated through application to late Holocene zooarchaeological mussel assemblages from north Texas. Taphonomically robust species are important regarding zooarchaeological and biogeographic interpretations based on mussel paleofaunas, and fragile species are important indicators of whether or not an assemblage is well preserved.